MDP, Pool safety trigger alarm

I’m halfway through my Year 12 Major Design Project and now need a hand turning the concept into a working prototype. The idea is simple: a small, battery-powered unit floats on the water, watches for an unusual splash or tilt, and fires a loud buzzer if something—or someone—hits the pool unexpectedly.

Hardware on hand
• Arduino-compatible board
• 3-axis tilt/accelerometer sensor
• Piezo buzzer (primary alarm)
• Optional LED and on-board Li-ion pack (solar top-up later)

What I’d like you to do
1. Draw up a clean wiring diagram that links the sensor, buzzer and microcontroller so I can reproduce it on a breadboard first, then on perf-board.
2. Write the Arduino sketch that:
– Reads the accelerometer, applies filtering, and compares movement against an adjustable threshold (potentiometer or software value).
– Ignores gentle ripples but reacts instantly to a sudden splash or 30-degree tilt.
– Drives the buzzer for a clear audible alert; LED support can sit in the code but remain optional for now.
3. Walk me through the logic in a step-by-step guide. I need to understand it well enough to document every decision in my design folio.
4. Coach me through bench-top testing in a small tub, then help fine-tune parameters once we shift to a larger prototype. Remote sessions or annotated photos are fine.

Acceptance criteria
• Arduino sketch compiles without warnings and reliably triggers only on genuine disturbances.
• Adjustable threshold works across at least three sensitivity levels.
• Buzzer sounds at ≥85 dB within 200 ms of detection.
• Clear PDF wiring diagram plus pin list.
• Step-by-step commentary (plain English) explaining each function, variable and threshold calculation.

If you’re comfortable with accelerometer filtering (Kalman or simple moving average), debouncing false positives and producing concise documentation, I’d love to get started right away.